1. Field of the Invention
The present invention relates to a method of manufacturing a porous body, a porous body, a method of manufacturing a device, a device, a method of manufacturing a wiring structure, and a wiring structure.
2. Description of the Related Art
In recent years, in order to cope with microfabrication and high integration of a semiconductor device, a multilayer structure wiring has become a mainstream. A Cu wiring has been applied to prevent propagation delay of a signal flowing in a wiring. In addition, as the method of forming a wiring, a dual damascene method has become a mainstream (JP1998-284600A (JP-H10-284600A)).
The dual damascene method is a technology for forming a wiring layer by forming a via trench structure in an insulating film by a method such as etching and filling the via trench structure with a wiring material such as Cu by an electrolytic plating method. For the insulating film, a low dielectric constant material is employed to suppress signal delay and as the low dielectric constant material, a porous silica film and the like are used.
In addition, in recent years, there has been proposed a method of using an imprint method for forming a via trench structure in an insulating film (Microelectronic Engineering, 110 (2013) 198).
The imprint method is a technology for transferring a fine pattern to a material by pressing a pattern-formed metal mold (generally also referred to as a mold or a stamper) against the material. As the imprint method, a method called a thermal imprint method or a photoimprint method has been proposed based on the transfer method thereof.
In the thermal imprint method, a mold is pressed against a thermoplastic resin heated to a temperature equal or higher than the glass transition temperature thereof, then the thermoplastic resin is cooled to a temperature equal or lower than the glass transition temperature, and the mold is released from the resin to thereby transfer a microstructure onto the resin on the substrate.
On the other hand, in the photoimprint method, a curable composition is photocured by photoirradiation through a light transmitting mold or a light transmitting substrate and then the mold is peeled off to thereby transfer a fine pattern to the photocured product. In this method, since imprinting is performed on an uncured product, heating under high pressure and high temperature is not required and a fine pattern can be easily formed. Further, the method makes imprinting possible at room temperature and thus can be applied to precision processing field of an ultrafine pattern for production of semiconductor integrated circuits and the like.
For example, as a photocurable composition for imprinting, silsesquioxane and the like are proposed (JP2008-168480A).